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hybrd1.c
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hybrd1.c
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/* hybrd1.f -- translated by f2c (version 20020621).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "cminpack.h"
#include "cminpackP.h"
__cminpack_attr__
int __cminpack_func__(hybrd1)(__cminpack_decl_fcn_nn__ void *p, int n, real *x, real *
fvec, real tol, real *wa, int lwa)
{
/* Initialized data */
const real factor = 100.;
/* Local variables */
int j, ml, lr, mu, mode, nfev;
real xtol;
int index;
real epsfcn;
int maxfev, nprint;
int info;
/* ********** */
/* subroutine hybrd1 */
/* the purpose of hybrd1 is to find a zero of a system of */
/* n nonlinear functions in n variables by a modification */
/* of the powell hybrid method. this is done by using the */
/* more general nonlinear equation solver hybrd. the user */
/* must provide a subroutine which calculates the functions. */
/* the jacobian is then calculated by a forward-difference */
/* approximation. */
/* the subroutine statement is */
/* subroutine hybrd1(fcn,n,x,fvec,tol,info,wa,lwa) */
/* where */
/* fcn is the name of the user-supplied subroutine which */
/* calculates the functions. fcn must be declared */
/* in an external statement in the user calling */
/* program, and should be written as follows. */
/* subroutine fcn(n,x,fvec,iflag) */
/* integer n,iflag */
/* double precision x(n),fvec(n) */
/* ---------- */
/* calculate the functions at x and */
/* return this vector in fvec. */
/* --------- */
/* return */
/* end */
/* the value of iflag should not be changed by fcn unless */
/* the user wants to terminate execution of hybrd1. */
/* in this case set iflag to a negative integer. */
/* n is a positive integer input variable set to the number */
/* of functions and variables. */
/* x is an array of length n. on input x must contain */
/* an initial estimate of the solution vector. on output x */
/* contains the final estimate of the solution vector. */
/* fvec is an output array of length n which contains */
/* the functions evaluated at the output x. */
/* tol is a nonnegative input variable. termination occurs */
/* when the algorithm estimates that the relative error */
/* between x and the solution is at most tol. */
/* info is an integer output variable. if the user has */
/* terminated execution, info is set to the (negative) */
/* value of iflag. see description of fcn. otherwise, */
/* info is set as follows. */
/* info = 0 improper input parameters. */
/* info = 1 algorithm estimates that the relative error */
/* between x and the solution is at most tol. */
/* info = 2 number of calls to fcn has reached or exceeded */
/* 200*(n+1). */
/* info = 3 tol is too small. no further improvement in */
/* the approximate solution x is possible. */
/* info = 4 iteration is not making good progress. */
/* wa is a work array of length lwa. */
/* lwa is a positive integer input variable not less than */
/* (n*(3*n+13))/2. */
/* subprograms called */
/* user-supplied ...... fcn */
/* minpack-supplied ... hybrd */
/* argonne national laboratory. minpack project. march 1980. */
/* burton s. garbow, kenneth e. hillstrom, jorge j. more */
/* ********** */
/* Parameter adjustments */
--fvec;
--x;
--wa;
/* Function Body */
/* check the input parameters for errors. */
if (n <= 0 || tol < 0. || lwa < n * (n * 3 + 13) / 2) {
return 0;
}
/* call hybrd. */
maxfev = (n + 1) * 200;
xtol = tol;
ml = n - 1;
mu = n - 1;
epsfcn = 0.;
mode = 2;
for (j = 1; j <= n; ++j) {
wa[j] = 1.;
}
nprint = 0;
lr = n * (n + 1) / 2;
index = n * 6 + lr;
info = __cminpack_func__(hybrd)(__cminpack_param_fcn_nn__ p, n, &x[1], &fvec[1], xtol, maxfev, ml, mu, epsfcn, &
wa[1], mode, factor, nprint, &nfev, &wa[index + 1], n, &
wa[n * 6 + 1], lr, &wa[n + 1], &wa[(n << 1) + 1], &wa[n * 3
+ 1], &wa[(n << 2) + 1], &wa[n * 5 + 1]);
if (info == 5) {
info = 4;
}
return info;
/* last card of subroutine hybrd1. */
} /* hybrd1_ */